Google recently announced that it plans to personalize everyone’s search results effective immediately. (Wondering how personalized search works? Check out Search Engine Land for a great overview.)
Essentially, this means that search results will be based on each individual user’s use history, rather than the relevance of websites to the search query.

Google will be watching what you click on in search results and it will learn that you favor particular sites. For example, if you often search and click on links from Amazon that appear in Google’s results, over time, Google learns that you really like Amazon.
In reaction to your clicking, Google gives Amazon a ranking boost. That means you start seeing more Amazon listings, perhaps for searches where Amazon wasn’t showing up before.
These results will be customized for each individual. For example, if your mom prefers Barnes & Noble, over time, Google will learn that she refers Barnes & Noble. Then, when your mom searches for books, she’ll be more likely to see Barnes & Noble listings.
Does this mean that SEO is dead? The answer is “no,” according to Danny Sullivan, who says, “SEO remains important to ensure that you’ve got that first shot at being considered. And the best tip in this new world of personalization remains the same. Make a good impression. Titles and descriptions are important, as is having outstanding content.”
Will personalized search impact your affiliate marketing business? It’s hard to say right now. Personalized search, although not really a new concept, has been taken to a new level by Google.
On-page SEO is certainly no less important than it was last week. Keep going with all of your on page SEO efforts. And remember that the importance of link building hasn’t diminished and off page SEO (article submission, forum posting, etc.) should probably be increased so that you can cast a wider net and be “relevant” to more individuals.
Google Now Personalizes Everyone’s Search Results

The “New Normal” That Deserves Extraordinary Attention